WO2024056434A1

WO2024056434A1 - Optically-powered ecg measurement nodes and ecg sensing networks

Info

Publication number: WO2024056434A1
Application number: PCT/EP2023/074215
Authority: WO
Inventors: Richard E Brown; Paul Franz REDDER; Bruce Geoffrey APPLETON
Original assignee: Koninklijke Philips N.V.
Priority date: 2022-09-12
Filing date: 2023-09-05
Publication date: 2024-03-21

Abstract

The present disclosure relates to optically-powered electrocardiogram (ECG) measurement nodes, ECG sensing networks comprising one or more ECG measurement nodes, and methods of taking ECG measurements using optically-powered ECG measurement nodes. Each optically- powered, non-conductive ECG measurement node is connectable to an ECG electrode and comprises a set of non-conductive fiber-optic cables, a measurement circuit, and an optical input circuit. The optical input circuit each of ECG measurement node is configured to convert an optical input signal into a DC power output and supply the DC power output to the measurement circuit in order to perform ECG measurements at the ECG measurement node.

Description

OPTICALLY-POWERED ECG MEASUREMENT NODES AND ECG SENSING NETWORKS

Field of the Disclosure

[0001] The present disclosure relates generally to electrocardiogram (ECG) measurements, and more specifically to optically-powered ECG measurement nodes and methods of taking ECG measurements using optically-powered ECG measurement nodes.

Background

[0002] An electrocardiogram (ECG) is a recording of electrical activity associated with the functioning of a subject’s heart and is one of the most meaningful biometric measurements concerning heart activity that can be measured non-invasively. Because an ECG may be generated in real-time, analysis of a subject’s ECG can be an efficient tool for determining a variety of heart conditions and/or necessary treatments (e.g., defibrillation, etc.).

[0003] In conventional ECG measurement systems, an electrode having an adhesive is attached to the subject at certain locations of the subject’s body and galvanic leads are connected to each electrode to measure electrical activity associated with the subject’s heart from each of those different locations. These electrical signals are then transmitted to an ECG monitor, which uses the combined information of the different electrical signals to generate an ECG. The ECG may then be displayed to a clinician or healthcare provider to review and act upon.

[0004] However, due to the nature of taking ECG measurements, detecting electrical pulses produced by the heart under certain conditions can be difficult, such as in environments subjected to high magnetic fields. For example, conventional ECG systems having conventional galvanic ECG leads may pick-up signal noise when in proximity to a magnetic resonance imaging (MRI) machine, resulting in signal degradation. Further, in a strong magnetic field, the galvanic ECG leads can be a source of radio frequency (RF) heating that could cause bums. Summary of the Disclosure

[0005] According to an embodiment of the present disclosure, non-conductive electrocardiogram measurement node is provided. The non-conductive electrocardiogram measurement node comprises: a set of non-conductive fiber-optic cables configured to transmit an optical input signal to the measurement node and transmit an optical output signal to an electrocardiogram monitor; a measurement circuit coupled to the set of non-conductive fiber-optic cables and configured to generate and output the optical output signal via the set of non-conductive fiber-optic cables, wherein the measurement circuit is connectable to an electrocardiogram electrode and the optical output signal corresponds to an electrocardiogram signal detected by the electrocardiogram electrode; an optical input circuit coupled to the set of non-conductive fiberoptic cables and the measurement circuit, wherein the optical input circuit is configured to receive the optical input signal via the set of non-conductive fiber-optic cables, to convert the optical input signal to a DC power output, to supply the DC power output to at least the measurement circuit, and to recover a clock signal from the optical input signal.

[0006] In an aspect, the set of non-conductive fiber-optic cables comprises a first cable configured to transmit the optical input signal to the measurement node and a second cable configured to transmit the optical output signal to the electrocardiogram monitor.

[0007] In an aspect, the optical input signal is a modulated optical signal having an embedded clock component.

[0008] In an aspect, the modulated optical input signal comprises at least one of a pulse width modulated optical signal, a frequency modulated optical signal, and an amplitude modulated optical signal.

[0009] In an aspect, the optical input circuit comprises a photovoltaic cell configured to convert the optical input signal to the DC power output.

[0010] In an aspect, the measurement circuit is reversibly connectable to the electrocardiogram electrode.

[0011] In an aspect, the set of non-conductive fiber-optic cables is connectable to a remote light source configured to generate the optical input signal transmitted to the measurement node via the set of non-conductive fiber-optic cables.

[0012] According to another embodiment of the present disclosure, an electrocardiogram sensing network configured to measure an electrocardiogram signal of a subject is provided. The electrocardiogram sensing network comprises a plurality of non-conductive electrocardiogram measurement nodes connectable to a plurality of corresponding electrocardiogram electrodes attached to the subject, wherein each non-conductive electrocardiogram measurement node includes: a set of non-conductive fiber-optic cables configured to transmit an optical input signal to the measurement node and transmit an optical output signal to an electrocardiogram monitor; a measurement circuit coupled to the set of non-conductive fiber-optic cables and configured to generate and output the optical output signal via the set of non-conductive fiber-optic cables, wherein the measurement circuit is connectable to an electrocardiogram electrode and the optical output signal corresponds to an electrocardiogram signal detected by the electrocardiogram electrode; an optical input circuit coupled to the set of non-conductive fiber-optic cables and the measurement circuit, wherein the optical input circuit is configured to receive the optical input signal via the set of non-conductive fiber-optic cables, to convert the optical input signal to a DC power output, to supply the DC power output to at least the measurement circuit, and to recover a clock signal from the optical input signal.

[0013] In an aspect, the electrocardiogram sensing network further comprises a remote light source, wherein each of the non-conductive electrocardiogram measurement nodes is connected to the remote light source via the set of non-conductive fiber-optic cables, respectively.

[0014] In an aspect, the electrocardiogram monitor is configured to generate the optical input signal that is transmitted to each the non-conductive electrocardiogram measurement nodes, and wherein each of the non-conductive electrocardiogram measurement nodes are synchronized based on the clock signal recovered from the optical input signal.

[0015] According to yet another embodiment of the present disclosure, a method of generating an electrocardiogram for a subject via an electrocardiogram sensing network is provided. The method comprises: generating an optical input signal via a remote light source; transmitting the optical input signal to the electrocardiogram sensing network, wherein the electrocardiogram sensing network comprises a plurality of non-conductive electrocardiogram measurement nodes connected to a plurality of corresponding electrocardiogram electrodes, each of the electrocardiogram electrodes being attached to the subject; generating, via the electrocardiogram sensing network, a set of optical output signals comprising a plurality of optical output signals, each optical output signal corresponding to an electrocardiogram signal detected at each of the plurality of non-conductive electrocardiogram measurement nodes; receiving the set of optical output signals at an electrocardiogram monitor; and generating the electrocardiogram for the subject based on the set of optical output signals.

[0016] In an aspect, generating the set of optical output signals includes, at each of the plurality of non-conductive electrocardiogram measurement nodes: receiving the optical input signal from the remote light source via a set of non-conductive fiber-optic cables coupled to each respective non-conductive electrocardiogram measurement node; generating, via an optical input circuit of each respective non-conductive electrocardiogram measurement node, a DC power output using the optical input signal; using the DC power output generated at each respective non-conductive electrocardiogram measurement node to power at least a measurement circuit of each respective non-conductive electrocardiogram measurement node; detecting, via the measurement circuit of each respective non-conductive electrocardiogram measurement node and the electrocardiogram electrode connected to the respective non-conductive electrocardiogram measurement node, an electrocardiogram signal; converting, via the measurement circuit of each respective non- conductive electrocardiogram measurement node, the detected electrocardiogram signal to an optical output signal, wherein the optical output signal contains electrocardiogram signal information; and transmitting, via the set of non-conductive fiber-optic cables coupled to each respective non-conductive electrocardiogram measurement node, the optical output signal to the electrocardiogram monitor, wherein the set of optical output signals comprises a plurality of optical output signals measured at the plurality of non-conductive electrocardiogram measurement nodes.

[0017] In an aspect, the optical input signal generated by the remote light source is a modulated optical signal having an embedded clock component.

[0018] In an aspect, the modulated optical input signal comprises at least one of a pulse width modulated optical signal, a frequency modulated optical signal, and an amplitude modulated optical signal.

[0019] In an aspect, the optical input circuit of each non-conductive electrocardiogram measurement node comprises a photovoltaic cell configured to convert the optical input signal to the DC power output.

[0020] These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiments described hereinafter. Brief Description of the Drawings

[0021] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments.

[0022] FIG. 1 is a block diagram of an optically-powered, non-conductive electrocardiogram measurement node illustrated according to aspects of the present disclosure.

[0023] FIG. 2 is a circuit schematic of an optically-powered, non-conductive electrocardiogram measurement node illustrated according to aspects of the present disclosure.

[0024] FIG. 3 is a circuit schematic of an optical input circuit of an optically-powered, non- conductive electrocardiogram measurement node illustrated according to aspects of the present disclosure.

[0025] FIG. 4A is a diagram of an electrocardiogram sensing network illustrated according to aspects of the present disclosure.

[0026] FIG. 4B is a block diagram of an electrocardiogram monitor illustrated according to aspects of the present disclosure.

[0027] FIG. 5 A is a flowchart of a method for generating an electrocardiogram for a subject via an electrocardiogram sensing network illustrated according to aspects of the present disclosure. [0028] FIG. 5B is a flowchart of a method for generating an electrocardiogram for a subject via an electrocardiogram sensing network illustrated according to further aspects of the present disclosure.

Detailed Description of Embodiments

[0029] The present disclosure is directed to optically-powered electrocardiogram (ECG) measurement nodes, ECG sensing networks comprising a plurality of optically-powered ECG measurement nodes, and methods of generating an ECG using such ECG sensing networks. As described herein, the optically-powered ECG measurement nodes eliminate the need for conductive ECG leads and the drawbacks associated therewith. As such, the embodiments described herein may find particular application in settings and environments subjected to high magnetic fields, or settings and environments where subjects may be subjected to high magnetic fields. [0030] With reference to FIGS. 1 and 2, various aspects of an optically-powered, non- conductive electrocardiogram (ECG) measurement node 100 are illustrated according to the present disclosure. As shown in FIG. 1, a block diagram of an ECG measurement node 100 is illustrated. Further, as shown in FIG. 2, a partial circuit schematic of an ECG measurement node 100 is illustrated according to one embodiment of the present disclosure. In general, as shown in FIGS. 1 and 2, the ECG measurement node 100 comprises at least a set of non-conductive fiberoptic cables 104, a measurement circuit 106, and an optical input circuit 108. It should be appreciated by those skilled in the art that the electronics 106, 108 of the ECG measurement node 100 may be packaged (i.e., include packaging 109) in a variety of ways for use in accordance with the present disclosure, and there are not discussed further herein.

[0031] The set of non-conductive fiber-optic cables 104 may be configured to transmit optical signals (e.g., coded light pulses) to and/or from the ECG measurement node 100. In particular embodiments, the non-conductive fiber-optic cables 104 can be configured to transmit an optical input signal to the ECG measurement node 100 and to transmit an optical output signal from the ECG measurement node 100 to an ECG monitor (not shown). In some embodiments, the set of non-conductive fiber-optic cables 104 comprises a single fiber-optic cable 104. In other embodiments, the set of non-conductive fiber-optic cables 104 comprises two or more fiber-optic cables 104. For example, as shown in FIG. 2, the set of non-conductive fiber-optic cables 104 comprises a first fiber-optic cable configured to transmit the optical input signal to the ECG measurement node 100, and a second fiber-optic cable configured to transmit the optical output signal from the ECG measurement node 100 to the patient monitor.

[0032] In embodiments, the measurement circuit 106 is coupled to the set of non-conductive fiber-optic cables 104 (e.g., at least one fiber-optic cable of the set of fiber-optic cables 104) and is configured to generate an optical output signal that contains ECG information. As used herein, the term “ECG information” refers to data (whether analog, digital, or optical) concerning electrical signals detected by one or more ECG electrodes 102. As will be appreciated by those of skill in the art, the ECG electrodes 102 may be variously embodied, but may include at least an adhesive layer 116 used to secure the electrode 102 to the skin of a subject and a conductive element 118 used to detect electrical activity when attached to the skin of the subject.

[0033] The measurement circuit 106 may include one or more components necessary for detecting and digitizing ECG signals / pulses, converting the digitized ECG signals / pulses into an optical output signal containing ECG information, and communicating the optical output signal over the set of non-conductive fiber-optic cables 104. For example, as shown in FIG. 2, the measurement circuit 106 may include a programmable gain amplifier (PGA) 120, an analog-to- digital converter (ADC) 122, and/or a digital-to-optical converter 124. As shown, each of the PGA 120, the ADC 122, and the optical converter 124 receive a power supply (VCC) and a recovered clock signal (CLK) from the optical input circuit 108 of the ECG measurement node 100. Accordingly, as discussed below, the measurement circuit 106 is optically-powered and the ECG measurement node 100 is synchronized with using the recovered clock signal (CLK).

[0034] In embodiments, the measurement circuit 106 of the ECG measurement node 100 is connectable to a respective ECG electrode 102. As shown in the example of FIG. 1, the ECG measurement node 100 includes a connector 110 that provides a secure physical and/or electrical connection 114 between the ECG measurement node 100 and a complementary connector 112 of the ECG electrode 102. In embodiments, the measurement circuit 106 of the ECG measurement node 100 is connected to the ECG electrode 102 via these connectors 110, 112. For example, these connectors 110, 112 may provide a connection 114 between the measurement circuit 106 and the respective ECG electrode 102 as shown in FIG. 2. In particular embodiments, the physical and/or electrical connection 114 is a reversible connection 114. That is, the ECG measurement node 100 may be reversibly connectable to one or more ECG electrodes 102 such that the ECG measurement node 100 may be reused. For example, connectors 110, 112 may be complementary connections of a snap-button.

[0035] In embodiments, the measurement circuit 106 of each ECG measurement node 100 can be configured to detect a separate analog ECG signal that corresponds to electrical pulses associated with the activity of a subject’s heart. These analog ECG signals can be small electrical pulses, which may be in the pV to mV ranges. Each of these separate analog ECG signals may be detected at different locations on the subject based on the placement of each corresponding ECG electrode 102. For example, in some embodiments, two ECG electrodes 102 may be attached to the subject at the subject’s left and right arms, and two separate analog ECG signals may be detected by the ECG measurement node 100 connected to each respective ECG electrode 102. In further embodiments, three or more pairs of ECG electrodes 102 and corresponding ECG measurement nodes 100 are attached to the subject at different locations of the subject’s body. In specific embodiments, the number of ECG electrode 102 and ECG measurement node 100 pairs may range from 1 to 12 pairs (e.g., 12 ECG electrodes 102 attached to a subject at different locations and 12 corresponding ECG measurement nodes 100 connected to a respective ECG electrode 102).

[0036] In embodiments, the measurement circuit 106 of each ECG measurement node 100 can be configured to convert the analog ECG signal detected at the ECG measurement node 100 to an optical output signal containing ECG information. In particular embodiments, the measurement circuit 106 of each ECG measurement node 100 may first convert the analog ECG signal detected to a digital ECG signal, and then convert the digital ECG signal to an optical output signal. For example, as shown in FIG. 2, the measurement circuit 106 includes an ADC 122 configured to convert an analog ECG signal into a digital ECG signal (i.e., SIG OUT), which is received by a digital-to-optical converter 124 configured to convert the digital ECG signal (SIG OUT) into an optical signal that may be transmitted using a non-conductive fiber-optic cable 104. As such, the measurement circuit 106 of each ECG measurement node 100 may be further configured to transmit the optical output signal to, for example, an ECG monitor, via the set of non-conductive fiber-optic cables 104.

[0037] In certain embodiments, the PGA 120 receives the analog ECG pulses from the ECG electrode 102, which are electrical signals. The ADC 112 converts the ECG pulses into digital ECG signals at a predetermined sampling frequency (e.g., 300 Hz). The optical converter 124 receives the digital ECG signals and converts them to optical ECG signals. The optical converter 340 may be a laser or an LED light source, for example. The optical converter 124 outputs the optical ECG signals to, for example, a patient monitor, via the set of fiber-optic cables 104. However, it should be appreciated that other arrangements of the measurement circuit 106 are possible.

[0038] As further shown in the examples of FIGS. 1 and 2, the ECG measurement node 100 includes an optical input circuit 108. The optical input circuit 108 of each ECG measurement node 100 may be coupled to the set of non-conductive fiber-optic cables 104 as well as the measurement circuit 106 of the same ECG measurement node 100. The optical input circuit 108 of each ECG measurement node 100 can be configured to receive the optical input signal from a remote light source via the set of non-conductive fiber-optic cables 104 and convert the optical input signal to a DC power output (VCC). In embodiments, the optical input circuit 108 of each ECG measurement node 100 may supply the DC power output (VCC) to at least the measurement circuit 106 such that the necessary power requirements for detecting and transmitting an ECG signal via the measurement circuit 106 are met (e.g., as shown in FIG. 2).

[0039] In embodiments, the optical input circuit 108 is further configured to recover a clock signal from the optical input signal received. That is, the optical input signal received by the optical input circuit 108 may contain an embedded clock signal used to synchronize operation of multiple ECG measurement nodes 100. According to aspects of the present disclosure, the optical input signal may be a modulated optical signal, such as a pulse width modulated optical signal, a frequency modulated optical signal, an amplitude modulated optical signal, and the like.

[0040] With reference to FIG. 3, an optical input circuit 108 of an ECG measurement node 100 is illustrated according to one embodiment of the present disclosure. As shown, the optical input circuit 108 is connected to a fiber-optic cable 104. The DC power converter 130 is configured to receive the optical input signal from the remote light source, and to convert the optical input signal to a corresponding electrical signal. By converting the optical input signal to the electrical signal, the DC power converter 130 recovers DC power embedded within the optical input signal. For example, when the optical input signal is a pulse width modulated optical signal, the magnitude of the DC power is indicated by the frequency and/or widths of the light pulses. In embodiments, the DC power converter 130 may be a photovoltaic cell or multiple photovoltaic cells, which converts optical signals directly into electrical signals using photovoltaic effect.

[0041] Further, as shown in FIG. 3, a clock recovery circuit 132 also receives the optical input signal and recovers an embedded clock signal from the optical input signal. In embodiments, the clock recovery circuit 132 may be an edge detector, phase detector, a frequency detector, or the like, depending on how the clock is optically encoded.

[0042] Generation of the DC power (VCC) and the embedded clock signal may be performed in any order or simultaneously. The DC power converter 130 may supply the DC power output (VCC) and the clock recovery circuit 132 outputs the recovered clock signal (CLK) to other components of the measurement node 106, as discussed above.

[0043] Turning to FIGS. 4A and 4B, also described herein are ECG sensing networks comprising a plurality of ECG measurement nodes 100 connected to a plurality of corresponding ECG electrodes. As shown, the ECG sensing network 400 includes a plurality of ECG measurement nodes 100, which are connected to a plurality of corresponding ECG electrodes 102 (not shown) attached to a subject 402. As discussed above, each of the pairs of ECG electrodes 102 and ECG measurement nodes 100 may placed at different locations on the subject’s body. Each ECG measurement node 100 may further be connected to an ECG monitor 430 via at least one or more sets of non-conductive fiber-optic cables 404. In other words, the ECG sensing network 400 may include the ECG monitor 430 and/or one or more of the components therein. [0044] As shown in FIG. 4B, the ECG monitor 430 can include an optical modulator 431, an optical demodulator 432, and a processor 433. The optical modulator 431 can be configured to receive a clock signal from a clock 437 and a light signal from a light source 438, to modulate the light signal and the clock signal using a compatible modulation technique, and to output a modulated optical signal with an embedded clock signal (also referred to as the optical input signal) to the ECG measurement nodes 100 via the respective input fiber-optic cables 404.

[0045] In embodiments, the light source 438 may be a laser or a light emitting diode (LED), and the optical modulator 431 may provide a pulse width modulated (PWM) optical signal with an embedded clock signal, which may be embedded via light pulses, for example. In further embodiments, the optical modulator 431 may provide a frequency modulated or amplitude modulated optical signal with the embedded clock signal. The frequencies and/or widths of the light pulses in the PWM optical signal and the embedded clock signal, for example, may be adjusted to suit the particular environment. For example, when the ECG sensing network is used in an MRI environment, certain frequencies can be avoided as to not interfere with the MR scanned image. A tunable configuration of the ECG module 430 allows all frequencies to be selected or avoided.

[0046] The optical demodulator 432 may be configured to receive optical ECG signals from the ECG measurement nodes 100 via the respective output fiber-optic cables 404, respectively, and to convert the ECG signals into corresponding electrical signals. The processor 433 can be configured to execute instructions stored in a non-transitory memory (not shown) for processing the electrical signals to provide a corresponding ECG wave to the output 440. The instructions may further cause the processor 433 to define characteristics of the ECG signals, such as the QRS complex, average beat, heart rate variability, RR interval, PR interval, and pulse rate, for example. The memory may be one or more non-transitory memories and/or data storage, including but not limited to, a magnetic disk storage, an optical disk storage, an array of storage devices, a solid- state memory device, and the like, including combinations thereof. [0047] The processor 433 is representative of one or more processing devices, and may be implemented by a general-purpose computer, a central processing unit, a computer processor, a microprocessor, a microcontroller, FPGAs, ASICs, a state machine, programmable logic device, or combinations thereof, using any combination of hardware, software, firmware, hard-wired logic circuits, or combinations thereof. A processor may also refer to a collection of processors within a single computer system or distributed among multiple computer systems, such as in a cloud-based or other multi-site application.

[0048] The output 440 may include any type of visual manifestation of the ECG traces. For example, the output 440 may include a display for displaying the ECG wave, such as a computer monitor, a television, a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a flat panel display, a solid-state display, or a cathode ray tube (CRT) display, a touch screen or an electronic whiteboard, for example. Alternatively, or in addition, the output 440 may include a printer, such as a thermal printer or an inkjet printer, for example, for printing the ECG wave. ECG wave may be displayed and/or printed together with textual and/or graphical information that classifies and/or interprets the ECG wave.

[0049] Turning to FIGS. 5A and 5B, also described herein are methods 500 of generating an electrocardiogram for a subject via an ECG sensing network 400 comprising a plurality of non- conductive, optically-powered ECG measurement nodes 100. In various embodiments, each of the plurality of non-conductive, optically-powered ECG measurement nodes 100 can comprise a set of non-conductive fiber-optic cables 104, a measurement circuit 106, and an optical input circuit 108 as described above.

[0050] In a step 510, the method 500 includes generating an optical input signal via a remote light source. In embodiments, the optical input signal may be generated using at least the remote light source 438. The light source 438 may be a component of an ECG monitor 430, which may further include an optical modulator 431. As discussed above, the optical modulator 431 can be configured to receive a clock signal from a clock 437 and a light signal from the light source 438, to modulate the light signal and the clock signal using a compatible modulation technique, and to generate the optical input signal with an embedded clock signal. In some embodiments, the modulated optical input signal comprises at least one of a pulse width modulated optical signal, a frequency modulated optical signal, and an amplitude modulated optical signal. A tunable configuration of the ECG module 430 allows all frequencies to be selected or avoided. [0051] In a step 520, the method 500 includes transmitting the optical input signal to the ECG sensing network 400. In embodiments, the optical input signal generated by the ECG monitor 430 may be transmitted to one or more of the optically-powered ECG measurement nodes 100 of the ECG sensing network via a corresponding set of non-conductive fiber-optic cables 104. For example, step 520 may involve transmitting a common optical input signal to each of a plurality of optically-powered ECG measurement nodes 100. In this manner, each ECG measurement node 100 can recover a common clock signal (CLK) and thereby be synchronized across each of the ECG measurement nodes 100 of the ECG sensing network.

[0052] In a step 530, the method 500 includes generating a set of optical output signals using the ECG sensing network 400. As discussed above, each ECG measurement node 100 can produce an optical output signal comprising ECG information. In embodiments, the set of optical output signals comprises an optical output signal from one or more ECG measurement nodes 100 of the ECG sensing network 400.

[0053] In particular embodiments, with reference to FIG. 5B, the step 530 of generating a set of optical output signals using the ECG sensing network can include one or more steps performed at each of the ECG measurement nodes 100. For example, at each of one or more ECG measurement nodes 100, the method 500 may include: receiving, in a step 531, an optical input signal via a set of non-conductive fiber-optic cables 104; generating, in a step 532, a DC power output using an optical input circuitl08; supplying or using, in a step 533, the DC power output to power at least a measurement circuit 106; detecting, in a step 534, an analog ECG signal via an ECG electrode operatively connected with a respective ECG measurement node 100; converting, in a step 535, the analog ECG signal to an optical output signal containing ECG information via the measurement circuit 106; and transmitting, in a step 536, the optical output signal to an ECG monitor 430 via the set of non-conductive fiber-optic cables 104.

[0054] In embodiments, the step 535 of converting the analog ECG signal comprises first converting the analog ECG signal to a digital ECG signal and then converting the digital ECG signal to an optical output signal, as discussed above.

[0055] In further embodiments, the ECG monitor 430 is configured to process the set of optical output signals and to generate an electrocardiogram for the subject based thereon. For example, as shown in the example of FIG. 5 A, the method 500 may include receiving, in a step 540, the set of optical output signals from one or more ECG measurement nodes 100 at the ECG monitor 430. [0056] Then, in a step 550, the method 500 can include generating an electrocardiogram for the subject based on the set of optical output signals using the ECG monitor 430. In particular embodiments, the ECG monitor 430 can include an optical demodulator 432 configured to receive optical ECG signals from the ECG measurement nodes 100 via the respective output fiber-optic cables 404, and to convert the ECG signals into corresponding electrical signals. A processor 433 of the ECG monitor 430 can be configured to then execute instructions stored in a non-transitory memory (not shown) for processing the electrical signals to provide a corresponding ECG wave to the output 440. The instructions may further cause the processor 433 to define characteristics of the ECG signals, such as the QRS complex, average beat, heart rate variability, RR interval, PR interval, and pulse rate, for example.

[0057] In a step 560, the method 500 may further include displaying the ECG. For example, the ECG may form at least part of an output (e.g., output 440), and the ECG monitor can include a display for displaying the output 440, as discussed above. Alternatively, or in addition, the output 440 may be printed physically. In either case, the ECG and/or output 440 may be displayed in a manner that a clinician or healthcare specialist may review and then act upon the information provided therein.

[0058] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0059] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

[0060] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0100] The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.

[0101] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.”

[0102] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified.

[0103] As used herein, although the terms first, second, third, etc. may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are only used to distinguish one element or component from another element or component. Thus, a first element or component discussed below could be termed a second element or component without departing from the teachings of the inventive concept.

[0104] Unless otherwise noted, when an element or component is said to be “connected to,” “coupled to,” or “adjacent to” another element or component, it will be understood that the element or component can be directly connected or coupled to the other element or component, or intervening elements or components may be present. That is, these and similar terms encompass cases where one or more intermediate elements or components may be employed to connect two elements or components. However, when an element or component is said to be “directly connected” to another element or component, this encompasses only cases where the two elements or components are connected to each other without any intermediate or intervening elements or components.

[0105] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively.

[0106] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0107] The above-described examples of the described subject matter can be implemented in any of numerous ways. For example, some aspects can be implemented using hardware, software or a combination thereof. When any aspect is implemented at least in partin software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or computer or distributed among multiple devices/computers.

[0108] The present disclosure can be implemented as a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product can include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure. [0109] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium can be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium comprises the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0110] Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network can comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

[0111] Computer readable program instructions for carrying out operations of the present disclosure can be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, comprising an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions can execute entirely on the user’s computer, partly on the user’s computer, as a standalone software package, partly on the user’s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, comprising a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider). In some examples, electronic circuitry comprising, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) can execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure.

[0112] Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to examples of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions.

[0113] The computer readable program instructions can be provided to a processor of a, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions can also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture comprising instructions which implement aspects of the function/act specified in the flowchart and/or block diagram or blocks.

[0114] The computer readable program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

[0115] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various examples of the present disclosure. In this regard, each block in the flowchart or block diagrams can represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks can occur out of the order noted in the Figures. For example, two blocks shown in succession can, in fact, be executed substantially concurrently, or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions.

[0116] Other implementations are within the scope of the following claims and other claims to which the applicant can be entitled.

[0117] While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

Claims

Claims What is claimed is:

1. A non-conductive electrocardiogram measurement node, the measurement node comprising: a set of non-conductive fiber-optic cables configured to transmit an optical input signal to the measurement node and transmit an optical output signal to an electrocardiogram monitor; a measurement circuit coupled to the set of non-conductive fiber-optic cables and configured to generate and output the optical output signal via the set of non-conductive fiberoptic cables, wherein the measurement circuit is connectable to an electrocardiogram electrode and the optical output signal corresponds to an electrocardiogram signal detected by the electrocardiogram electrode; an optical input circuit coupled to the set of non-conductive fiber-optic cables and the measurement circuit, wherein the optical input circuit is configured to receive the optical input signal via the set of non-conductive fiber-optic cables, to convert the optical input signal to a DC power output, to supply the DC power output to at least the measurement circuit, and to recover a clock signal from the optical input signal.

2. The non-conductive electrocardiogram measurement node of claim 1, wherein the set of non-conductive fiber-optic cables comprises a first cable configured to transmit the optical input signal to the measurement node and a second cable configured to transmit the optical output signal to the electrocardiogram monitor.

3. The non-conductive electrocardiogram measurement node of claim 1, wherein the optical input signal is a modulated optical signal having an embedded clock component.

4. The non-conductive electrocardiogram measurement node of claim 1, wherein the modulated optical input signal comprises at least one of a pulse width modulated optical signal, a frequency modulated optical signal, and an amplitude modulated optical signal.

5. The non-conductive electrocardiogram measurement node of claim 1, wherein the optical input circuit comprises a photovoltaic cell configured to convert the optical input signal to the DC power output.

6. The non-conductive electrocardiogram measurement node of claim 1, wherein the measurement circuit is reversibly connectable to the electrocardiogram electrode.

7. The non-conductive electrocardiogram measurement node of claim 1, wherein the set of non-conductive fiber-optic cables is connectable to a remote light source configured to generate the optical input signal transmitted to the measurement node via the set of non-conductive fiberoptic cables.

8. An electrocardiogram sensing network configured to measure an electrocardiogram signal of a subject, the electrocardiogram sensing network comprising: a plurality of non-conductive electrocardiogram measurement nodes connectable to a plurality of corresponding electrocardiogram electrodes coupled to the subject, wherein each non- conductive electrocardiogram measurement node includes: a set of non-conductive fiber-optic cables configured to transmit an optical input signal to the measurement node and transmit an optical output signal to an electrocardiogram monitor; a measurement circuit coupled to the set of non-conductive fiber-optic cables and configured to generate and output the optical output signal via the set of non-conductive fiberoptic cables, wherein the measurement circuit is connectable to an electrocardiogram electrode and the optical output signal corresponds to an electrocardiogram signal detected by the electrocardiogram electrode; an optical input circuit coupled to the set of non-conductive fiber-optic cables and the measurement circuit , wherein the optical input circuit is configured to receive the optical input signal via the set of non-conductive fiber-optic cables, to convert the optical input signal to a DC power output, to supply the DC power output to at least the measurement circuit, and to recover a clock signal from the optical input signal.

9. The electrocardiogram sensing network of claim 8, further comprising a remote light source, wherein each of the non-conductive electrocardiogram measurement nodes is connected to the remote light source via the set of non-conductive fiber-optic cables, respectively.

10. The electrocardiogram sensing network of claim 8, wherein the ECG monitor is configured to generate the optical input signal that is transmitted to each the non-conductive electrocardiogram measurement nodes, and wherein each of the non-conductive electrocardiogram measurement nodes are synchronized based on the clock signal recovered from the optical input signal.

11. A method of generating an electrocardiogram for a subject via an electrocardiogram sensing network, the method comprising: generating an optical input signal via a remote light source; transmitting the optical input signal to the electrocardiogram sensing network, wherein the electrocardiogram sensing network comprises a plurality of non-conductive electrocardiogram measurement nodes connected to a plurality of corresponding electrocardiogram electrodes, each of the electrocardiogram electrodes being attached to the subject; generating, via the electrocardiogram sensing network, a set of optical output signals comprising a plurality of optical output signals, each optical output signal corresponding to an electrocardiogram signal detected at each of the plurality of non-conductive electrocardiogram measurement nodes; receiving the set of optical output signals at an electrocardiogram monitor; and generating the electrocardiogram for the subject based on the set of optical output signals.

12. The method of claim 11, wherein generating the set of optical output signals includes, at each of the plurality of non-conductive electrocardiogram measurement nodes: receiving the optical input signal from the remote light source via a set of non-conductive fiber-optic cables coupled to each respective non-conductive electrocardiogram measurement node; generating, via an optical input circuit of each respective non-conductive electrocardiogram measurement node, a DC power output using the optical input signal; using the DC power output generated at each respective non-conductive electrocardiogram measurement node to power at least a measurement circuit of each respective non-conductive electrocardiogram measurement node; detecting, via the measurement circuit of each respective non-conductive electrocardiogram measurement node and the electrocardiogram electrode connected to the respective non-conductive electrocardiogram measurement node, an electrocardiogram signal; converting, via the measurement circuit of each respective non-conductive electrocardiogram measurement node, the detected electrocardiogram signal to an optical output signal, wherein the optical output signal contains electrocardiogram signal information; and transmitting, via the set of non-conductive fiber-optic cables coupled to each respective non-conductive electrocardiogram measurement node, the optical output signal to the electrocardiogram monitor; wherein the set of optical output signals comprises a plurality of optical output signals measured at the plurality of non-conductive electrocardiogram measurement nodes.

13. The method of claim 11, wherein the optical input signal generated by the remote light source is a modulated optical signal having an embedded clock component.

14. The method of claim 11, wherein the modulated optical input signal comprises at least one of a pulse width modulated optical signal, a frequency modulated optical signal, and an amplitude modulated optical signal.

15. The method of claim 11, wherein the optical input circuit of each non-conductive electrocardiogram measurement node comprises a photovoltaic cell configured to convert the optical input signal to the DC power output.